Hello everyone, I just signed up to the forum.

I have a '99 LHS (3.5 v6). About 2 years ago, my water pump locked up causing my timing belt to melt over time until it snapped. It was pretty bad damage. I had to replace the starter, tensioner pulley, crank sprocket, water pump, thermostat, all belts, 3 exhaust valves on the left head and have it shaved off since it was warped. The car was running great, getting great gas mileage however i was experiencing some cooling/heating issues.

During winter, it would never get hot unless I came to a stop and let the car idle for a while. During summer (now), the car has been running hot. Finally it gave out on me last wk, overheated and started "clicking". Before taking the engine apart, I did some tests: good compression on each cylinder 150psi+, max of 13% loss on the leak test, oil on most of the plugs.

I took the heads to a shop to get them checked. They did a compression and a vacuum check; found out that some of the valve seats were leaking. Afterwards, they saw a few chips on the lobes of the right cam so replaced it. They also put all new valve seats and fixed 4 of the guides that were loose. I replaced the water pump and tested the thermostat, which seemed to be working fine. I also saw that 1/8" of the timing belt was literally shaved off on the outside perimeter; I have no idea what caused it.

Anyways, before I start putting the car back together, I'm trying to figure out the cooling/heating problem. I'd hate to put it back together and break down again. I'd appreciate any help.

 

incorrect thermostat?

clogged radiator fins?

clogged radiator?

radiator fans not working?

thats all it could be.. unless you are some scientist using unconventional liquids in the radiator.